1. Field of the Invention
The present invention relates to a connector for a data card, in particular to a data card connector for transferring data between a communication device and a data card.
2. Description of the Prior Art
Data cards take various forms and those used, for example, in cellular phones, may include passive memory cards (i.e., especially a ROM) or an active processor card. An example of the latter is a smart card, which includes a memory as an integrated circuit, commonly referred to as a xe2x80x9cchipxe2x80x9d, in which information is stored. The smart card may contain a subscriber identity module (SIM). Also, in addition to the subscriber identity information, such as a subscriber identifying telephone number, and personal identification number (PIN), the smart card may store for example, call charge information (i.e., a charge meter), a telephone number index, or false pin entries.
SIM cards are currently available in two sizes. The functionality of the SIM is the same for each, it is essentially that the physical dimensions are different. One is a credit card size SIM, and the other is a plug in SIM about 15 mm by 20 mm.
Other active processor cards include expansion cards which typically provide a communication device with additional functions, such as a modem function, or provide a driver for an external device.
Traditional data card holders are placed inside communication devices like mobile phones. Usually the battery pack powering the phone electronics has to be removed and the SIM card can be inserted by the user into a SIM card reader compartment which is closed by a cover or any other holding mechanism. After insertion of the card the battery pack is put in place and the users activates the power key of the phone. Now a microprocessor starts reading out information from the SIM card and asks the user for example for entering his PIN number if this application is activated. After the user has entered the correct PIN number the phone registers to the cellular network with the phone number read out from the SIM card and a phone calls can be established.
Other kinds of mobile phones, namely those phones which are mainly used in cars today and therefore now referred as to car phones, comprise usually a fixed unit installed at any convenient place in the car, e.g., in the boot and a handset comprising usually a keyboard and a display for operating the car phone and a loudspeaker and a microphone for communication.
The handset can for example be stored in a handset holder within the armrest besides the driver or at the dashboard of the car when it is not to be used. The car phone could be further equipped with devices for handsfree operation of the car phone and handsfree communication.
In early times the car phones usually provided a compartment for the SIM card in the fixed unit, but as this is fixed, e.g., installed in the boot of the car, it is inconvenient for the user to insert the card. As an alternative the SIM card compartment could be positioned inside the handset holder or within the handset itself. In the latter case usually a credit card sized SIM card is slidably engaged into the card holder of the handset.
However, because of the sliding movement of the card relative to the contacts of the card holder this way, there is a risk that the contacts, possibly even the contact pads on the card, may be damaged.
A variety of patent applications are published (e.g., GB 2 250 846) disclosing data card holders wherein the SIM card is inserted into a card receiving cover which is hingedly mounted on the main body of the communication device and on closing the cover the SIM card is pressed into the holder compartment and thereby the contacts of the SIM card are coupled to the contacts within the card holder.
U.S. Pat. No. 5,718,609 to Braun et al. describes a way in which a SIM card may be shielded during use. This is achieved by using a conductive SIM card holder, and electrically grounding the conductive holder.
Handheld mobile phones where the battery pack is usually removed before the SIM card can be inserted are powered off during this procedure. Car phones with a handset comprising a SIM card reader are not necessarily powered of as the car phone is connected to the car battery all the time. This could lead to an undefined condition of the car phone electronics, especially while the SIM card is slidably engaged to the card reader because not all contacts of the SIM card might be coupled to the SIM card reader contacts during insertion or, even worse, the SIM card contacts are coupled to the wrong SIM card reader contacts during insertion of the SIM card which may also damage the SIM card.
According to the invention there is provided a data card connector comprising: a housing defining an aperture for receiving a data card; and electrical connectors for coupling a data card and a cover movable between an open position and a closed position, wherein the data card connector further comprises an indicator for indicating whether the cover is in the open position or in the closed position.
By this indicator it is secured that the contacts between the data card and the data card connector are closed before any data contact from other electronics, e.g., electronics to read out the data card, is made to the data card before the cover is in the closed position. Furthermore the power supply for the data card can for example be turned on after it is indicated that the cover is in the closed position. Any damages to the data card because of unsecure electrical contact to the data card during the insertion of the data card is prohibited.
The indicator is preferably a switch. The switch can for example be in the closed position when the cover is closed or in the opened position when the cover is open.
Preferably the switch comprises electrical contact elements in the cover and the aperture for receiving the data card. When the cover is opened the contacts in the aperture and in the cover are not connected with each other and the switch is open. After the cover is closed the contacts have contact with each other and the switch is closed and indicated the cover closed position.
The construction of the switch preferably comprises a contact plate at the inner surface which is directed towards the aperture and the aperture comprises two contact springs directed towards the cover and when the cover is in the closed position the contact plate connects the contact springs for indicating the cover closed position.
Further the indicator indicates the cover position to a control unit and the control unit establishes a data connection to the electrical connectors upon cover-closed indication. This control unit could be a microprocessor that reads out a subscriber identifying telephone number and/or the personal identification number (PIN).
The data connection between the data card and the control unit is established when the data card is inserted and the cover-closed position is indicated.
Furthermore the control unit generates a data-card-missing signal after the data connection to the electrical connectors is established and no data card is inserted and the cover-closed position is indicated.
The cover of the data card is preferably slidably engageable with the housing to close off the aperture.
According to an embodiment of the invention the cover applies a force to the data card which presses the data card into the aperture and this way the data card contacts against the electrical connectors during the sliding engagement from the cover open to the cover closed position.
Preferably the cover comprises at least one guiding rail applying the force for pressing down the data card.
The longitudinal movement of the data card is limited by stops when the cover is sliding from the cover open position to the cover closed position and when the cover is in the closed position.
Preferably the data card contacts are coupled to the electrical connectors during the sliding engagement from the cover open to the closed position before the indication means indicate the cover closed position.
According to another aspect of the invention there is provided an interface for a communication device comprising a data card connector for the transfer of data between the card and the device.
According to a further aspect of the present invention there is provided a communication device comprising such an interface.